1. Field of Invention
The present invention relates to a method of body surface non-invasive detection of changes in molecular structures of organism tissues, and also relates to a dedicated apparatus for detecting changes in molecular structures of organism tissues.
2. Description of Prior Art
Survival for cancer patients depends largely on early detection. Thus, an important goal in cancer research is to develop accurate, quick, convenient and inexpensive methods to detect cancer early. Iconography methods, e.g. CT and MRI etc, to detect pathologic changes inside the human body via the “space-occupying effect” are now commonly used in clinics. A restriction of these methods is that a lesion cannot be detected before it has attained a large enough size (>1 cm in diameter). Concerning endoscopic and biopsy methods, a disadvantage is that patients may suffer from the long, invasive sampling process. Therefore, alternative approaches for early diagnosis of cancer are needed.
Infrared spectroscopy is a sensitive probe to reflect molecular structure. It is known that every substance has its own characteristic infrared spectrum, i.e. only absorbing infrared rays of some wavelengths but not other wavelengths, so the characteristic infrared absorption spectrum can be used for qualitative analysis of the substance. Moreover, the concentration of one component is proportion to the absorbance, so the characteristic infrared absorption spectrum can also be used for quantitative analysis of the substance. At present, infrared spectrometers are often used to measure absorbance (or transmittance) of substances to infrared radiations to study changes of molecular structure. Organism tissues comprise nucleic acid, poly-saccharide, protein, lipid and some other bio-molecules, and the compositions and structures of these biological molecules are different between normal cases and pathologic conditions. Based on this principle, someone has already used infrared spectrums to detect cancer cells, for example, first disclosed in Benedetti, Applied Spectroscopy, 1986, 40, 39. However, such detection also requires complex sample preparation techniques, and is time-consuming and invasive. Therefore, there is an urgent need for developing a non-invasive method capable of detecting pathologic changes of organism tissues at early stage.
Fourier transform infrared spectroscopy (abbreviated as FT-IR) is a most widespread method. At present, Fourier transform infrared spectrometers are mainly made up of light source, optical measuring system, computer data processing system, computer interface and electronic circuit system, etc. Among those, the optical measuring system is used for transmitting optical information and detecting and collecting data; the computer is used for processing data and controlling operation of the apparatus. Fourier transform infrared spectrometers can simultaneously transmit lights of all wavelengths to the detector, where the received signal is an interference pattern. After capturing the interference pattern, the computer converts it into a spectrogram by fast Fourier transform method. That is, the different absorption at every wavelength in the interference pattern is discriminated one by one (so-called Fourier transform is that sine or cosine functions in time domain and those in frequency domain are transformed to each other). (see Wu Jinguang, et al., “Modern Fourier Transform Infrared Spectroscopic Technologies And Applications”, Science and Technology Press, 1994).
FT-IR spectrometers at present exhibit various types and models, such as research type, analytical type, general type and purpose-specific type, and the like. When whichever type of spectrometer is used to detect a sample, a certain amount of the sample to be tested needs to be taken out and then placed onto related attachments inside the sample chamber of the infrared spectrometer to be measured. Sometimes the sample needs to be processed in advance in order to be suitable for measurements, for example, the biological sample is subject to homogenization process and the like. Such method is not only time-consuming, but also incapable of detecting organisms directly. Moreover, it will be an invasive way for the biologic sample measurement. Therefore, it is necessary to improve the Fourier transform infrared spectrometer to have, for example, a dedicated detection apparatus capable of sampling on the surface of organisms and then directly performing measurements, so that it can be directly applied to detect organisms such as human bodies. To do this, since 1995, we have measured and studied various in vitro tumors, in vivo tumors during operations and human body surfaces of tumor regions using the technology of FTIR in connection with mid-infrared fiber optics (Spectroscopy and Spectral Analysis, Vol. 16, No. 5, pp 22-25, October 1996, and ibid, Vol. 24, No. 5, pp 628-630, May 2004). It is found in researches that it is impossible to diagnose states of tumors only by one spectrum detection; also found that fibers of chalcogenide is too fragile and damageable, and fibers of silver halide have short lifetime, all of which are not suitable for clinic usage; and particularly found that infrared spectra of pathologic changes in some gland tumors (in vitro tumor tissues) have same variation regularities as those of corresponding regions non-invasively detected in vivo. Therefore, there exist needs for a method and apparatus and means thereof suitable for clinic usage, which can diagnose the property and the pathologic change degree of a tumor in a region by quickly and non-invasively detecting the infrared spectrum of the corresponding human body surface.